Major technology brands behind more than 30 of the top Apple iPhone applications, including Facebook, Twitter, and Foursquare, have received letters from U.S. lawmakers requesting information on how the apps collect consumer data.

The letters were sent out on Thursday to companies with products in the App Store's "iPhone Essential" area, as a part of an ongoing inquiry by the U.S. House Energy and Commerce Committee, and they were given until April 12 to respond to the request.

"Last month, a developer of applications ('apps') for Apple's mobile devices discovered that the social networking app Path was accessing and collecting the contents of his iPhone address book without having asked for his consent," read the committee's letter to Facebook. "Concerns were subsequently raised about the manner in which apps can access photographs on Apple's mobile devices. We are writing to you because we want to better understand the information collection and use policies and practices of apps for Apple's mobile devices with a social element."

Since the discovery lawsuits have been mounted by consumers against both the app's developers and Google and Apple.

Earlier in March a lawsuit was mounted at the U.S. District Court for the Western District of Texas accusing 18 companies, including Facebook, Apple, Twitter and Yelp, of distributing privacy-invading mobile apps.

About the author

Alastair has worked as a reporter covering security and mobile issues at V3 since March 2012. Before entering the field of journalism Alastair had worked in numerous industries as both a freelance copy writer and artist.